Nissan planned for 3 carb Z

[deadflo]

Hey folks, I have an interesting backlog of old road and ttrack and car and Driver mags from the 70's. I love to peruse them time to time (although my wife thinks I'm a compulsive collector).

Anyway a few days back I stumbled on a 1970 issue.

Contained therin on a page devoted to miscelaneous ramblings was a report from Japan on the then new Z. The mag(Rand T) had already run the road test of the 240-Z

But this was a report from the Tokyo auto show of 1970. It mentioned the Z432 vehicle, that was for domestic sale only ..then mentioned that Nissan was seriously considering a triple carbed 240Z for sale in the US by 1971. It would have been an upscale more expensive model utilizing SOLEX carbs. Anyone ever hear any more about this concept? Did they ever sell such an item in the home market?

Kats, maybe some of your Nissan connections may know?

[2ManyZs]

I seem to remember reading about it being proposed for the US.

I think at the time the major stumbling block would have been the emissions certification that could have caused it to be passed over. If anything could have killed it as proposed, it probably was getting it certified for sale in the US with all the new emissions rules that were being passed in the early 70's.

I'd bet if Mr. K could have had his way, the US and the rest of the world would have received the 432R's, or a very close copy of it.

[alien-e]

I'm not sure where I read this, but the big reason the 4 valve per cylinder, 3 Carb, 2 cam setup on the 432 didn't make it to the US was that the BRE team was able to pull similiar HP and Torque numbers from the standard L24 and E31 head in the 240 with slight modifications.

My guess is that it didn't make sense to Nissan Japan to put money into production (or sourcing) of so many different engine parts (carbs, intake, head, cams, valves, exhaust, valve covers, etc...). Well, that and the reason that 2ManyZs stated about emissions.

[HS30-H]

Not true, and I doubt if Mr K could give a damn about the S20 engine seeing as it was from a 'rival' division within Nissan. The reason it never went to America - or anywhere else - is because Nissan lost money on every one they made. He never even trusted you with a 5-speed transmission initially, did he?

The BRE story was almost certainly written by an American, or even started by Pete Brock himself. The S20 was fitted to the Z before Pete Brock even saw an L24 engine. The L24 was a good engine, but don't forget it also had a 400cc head start on the ( standard tune ) S20 engine.

I'm sure the engineers at Nissan were really pleased that BRE were able to 'teach' them how to race tune an engine, just like some of the Works 240Z rally team drivers were able to 'teach' the Nissan race engineers the 'difference between oversteer and understeer'.............:cheeky:

[deadflo]

So Alan what's your read on the first thread of this post about the triple solex carb? The story was written by Jack Yamaguchi, who was Road and Tracks man in Tokyo in 1970, do you know why it never made it into production?

BTW, saw your input in the Classic and sportscar this month. Whats the scoop on you being allowed into the Nissan musum? enlighten uis as to its contents....

[HS30-H]

Hi deadflo,

Well, you can bet ( as 2ManyZs pointed out ) that the BIG problem was with the ever-tightening emissions regs of that period, but don't rule out the long-reaching effects of the OPEC-triggered Oil Crisis and the chaos it caused.

In fact, Nissan offered a triple carburettor conversion for the L20 and L24 engines through their Japanese-market Sports Option lists just about from the beginning of sales in late 1969 / early 1970. Most of the stuff in their Sports Option lists was never offered in the Export markets. So the Factory-blessed parts were out there, but only as a private bolt-on. Once these had been made available to the general public as an option ( through Datsun Competition in the USA market ) it would have made little sense to make a production version with them already installed. The only reason they would have done that would be for homologation purposes - which was not necessary if they were in the Sports Options list.

The general trend during the early to mid Seventies was for major volume manufacturers to become more and more conservative with their production models. Triple carbs for the L-series 6 would have probably been frowned on by the motoring press, and seen as unnecessary.

Nissan apparently had plans to sell a higher-spec Z in selected Export markets, and one of the ideas was to sell a version of the car sporting some of the aerodynamic mods that were being used on the domestic racers of the time. In the end, only the ZG model made it out of the Factory and even that was for the Domestic market only. If Jack Yamaguchi got a sniff of a tri-carb model being mooted then you can bet it would probably have been planned for it to sport the aero package too - so it was most likely the early planning for the ZG that he had heard about. This was considerably tamer than it was originally planned to be, and had the same mechanicals as other HS30 models.

Nissan didn't really give up on the idea of a higher-spec or premium level Z for a long time. In fact, Nissan seem to have been still enamoured with the aerodynamic package as a possible production model when the RS30 / RLS30 models were launched. They never went through with it.

Jack Yamaguchi could well have been hearing about plans to sell the S20-engined variant to the Export market.. The 432 was seen as the 'premium' S30 model in the Japanese market until it the HS30 models debuted there in late 1971. Production still continued until as late as 1973, but the car was never a big seller due to its relatively high cost, perceived complexity and the fact that it was a 2-seater. The sporty family man of the time would choose a Skyline GT, GTX or even GT-R whilst the richer enthusiast could choose to go with an Italian or German import. The 432 needed careful running and maintenance, and most owners didn't know how to look after it. It cost a lot to produce the S20 engine and its quite understandable that it would never make a mass-market high seller.

Alan T.

[HS30-H]

Hi deadflo,

You asked about me being allowed into Nissan's 'museum'.

In fact, it was their storage facility at Zama - for many years known as the "Nissan Memorial Sports Hall" - where they keep most of their collection of old cars. Its a mixture of old production models, prototypes and race cars. They also have many cars that are on loan to other museums and temporary displays around Japan. Its not really a proper museum ( more's the pity ) as they don't have access for the general public yet. However, there are plans afoot for a proper museum-type facility soon ( don't hold your breath! ).

You can read about the visit here:

Nissan's collection of old cars

Cheers,

Alan T.

[kats]

Hello,

I have a letter size catalog for the U.S. 240Z "copyright,1969,

by Nissan Motor Company,Ltd"

There is a shot for the engine,it got 3 Mikuni Solex carbs.

The discription says "...The powerful OHC,2393cc, 6 cylinder engine generates 175 hp at 6800 rpm..." 175 hp

175 hp

This catalog is very very early stage made,so the tings happened I think.

I would like to tell some "general understanding" about S20 engine in japan.I do not mean they are 100% right,or true or fact.

Simply many japanese owners and journalists have been saying about these.You may find something,its up to you.

They are,

#1 S20 engine is very sensitive,it is difficult to keep its condition

#2 Some journalists said S20 engined car(Z432,Skyline GTR) was so hard to get its catalog performance. Some japanese car magazines tested S20 engined car during 1970's,they were always under powered.Finally, factory racing tuned car was brought to the track,it proved catalog performance.

#3 Mr.Nanba(team manager of safari rally 1970's also he was a test driver of S30 prototype) said the reason of safari car has L24 is duarable,simple,easy to maintain.He said S20 engine is so nervous,it was easy on the track but it was not suitable for much severe condition like the rally.He also mentioned S20 engine was regarded as a memorial featuring of Prince R380 in the company.

He said like this,"as an engineer,the L24 is the best for racing "

#4 S20 engine is very heavy,heavier than L24.Not mentioned severe vibration from GTR,but Z432 had that problem.Some times racing Z432R blowed its mission and gear carrier.

S20 engine was good for GTR chassis,not good for S30 chassis.

If you look closely at engine mounting of S20 in the Z432,you will fined mounting struts are stressed by heavy S20 engine.Mr.Nishi (proffessional restorer)said so many Z432s were brought in his factory,their mounting struts were always cracked.He siad nearly 90% of them.

S20 engine was made for GTR,this is true.Because when S20 engine was born,S30 was not born yet.

And Mr.Uemura(test driver of 240Z in the U.S. also he was a engineer of S30's suspention and chassis)

said that first they did not expect to install S20 into S30,suddenly the top of Nissan ordered to do that.All the engineers had to rearrange chassis for S20 engine.

I think if S20 engine was planed to install from the bigining of developing S30,engineers could design for mounting engine much better.If it could done,other chassis lay out could be much different from now.

Japanes race seen,S20 engined Z432R was faded out gradually

due to its vibration problem and factories found L24 engine car was easy to handle and has a good perfomance.

I like S20 engine,it is a romantic for me.Very high technical compornents and sexy sound.If I have a lot of money,I want to buy Z432.

kats

[v12horse]

That is really interesting Kats. Were there Z432's that went through the rigorous testing that the L-series powered s30's went through? Were the mounting points reinforced compared to the L-series? I do not know a whole lot about these cars, but I do agree with you Kats- The s30 with a S20 is a very sexy machine. I would love to hear one someday. Own one....

Ben

[v12horse]

I was reading in a Road and Track magazine from 1974. It was the one with the Fairlady 260z 2/2 with a G-nose on the cover. One very interesting part about the reading was that it stated that Nissan Motor co. was thinking about installing the LY engine in the 260z. We all know that this did not happen , but was this something that Nissan was really contemplating? I am sure that it would be too expensive to intsall the crossflow SOHC LY head with triple Mikuni's on a production car, but it would have been very cool. It would have been the Z432 of the 260z. Hehehe, Z431. Hehehehe. It was really interesting to read about it though.

Ben